It has been known to make insulation material comprising ceramic fibers by first forming a slurry of the fibers. For example, in U.S. Pat. No. 3,935,060, it is taught to mix together ceramic fiber and a binder which is felted, then dried and fired. It is taught in this manufacture of fibrous insulation to thoroughly mix together the slurry materials. Thus, the mixture is subjected to high shear mixing to form a uniformly dispersed slurry.
It has also been known to slurry together ceramic fibers and a colloidal material such as colloidal silica for providing refractory shaped articles. Thus, in U.S. Pat. No. 4,737,326, there is disclosed bringing together ceramic fibers and colloidal silica in a process eventually producing a molded refractory article. For providing the initial dispersion, the slurry is processed under high speed mixing to provide a well mixed dispersion. The slurry can be mixed with a flocculating agent, hot molded under pressure and sintering temperature, to provide the desired shaped article.
It has also been known to prepare refractory ceramic fiber articles by a heating and freezing process. In U.S. Pat. No. 5,120,477, it has been disclosed to saturate a ceramic fiber mat with a colloidal silica suspension and then to freeze the mat. Thereafter, heating of the mat is used to remove water and the resultant product is again saturated with colloidal silica. The mat can be molded prior to freezing as well as compressed prior to freezing.
It would still be desirable to make a refractory fiber product, i.e., a compressed, shaped product, which can be an insulation product having both desirable strength and insulation properties as well as flexibility. It would also be worthwhile to provide such a product without resorting to special or expensive processing techniques, e.g., freezing and heating, or high speed mixing of slurries. It would be further desirable if such product could have an appealing, textured surface, and an aggregate type body.